ERIE, Colo. (AP) -- Three construction workers have been injured in an explosion and partial roof collapse at a middle school east of Boulder.
Erie Middle School was closed for summer break at the time of the explosion Wednesday.
Mountain View Fire and Rescue spokeswoman Laura McConnell says two workers were transported to the hospital by ambulance and one was flown, but details about their condition weren't known.
School district spokesman John Poynton told the Daily Camera that initial reports indicate a water heater may have exploded.
Students aren't set to return to class until Aug. 16.
Erie is about 14 miles northeast of Boulder.